Organic compositions containing salts of amines and substituted acetic acids as corrosion inhibitors

ABSTRACT

ORGANIC COMPOSITIONS ARE PROVIDED CONTAINING, AS A CORROSION INHIBITOR, SALTS OBTAINED BY REACTING AN IMIDAZOLINE OR A DIAMINE WITH AN ALPHA-SUBSTITUTED ACETIC ACID.

United States Patent 3,775,320 ORGANIC COMPOSITIONS CONTAINING SALTS OFAMINES AND SUBSTITUTED ACETIC ACIDS AS CORROSION INHIBITORS Mario Vigo,Portici, Italy, and Fritz A. Buehler, Cherry Hill, N..I., assignors toMobil Oil Corporation No Drawing. Filed Oct. 5, 1971, Ser. No. 186,818Int. Cl. Cm 1/48 US. Cl. 252-33.6 7 Claims ABSTRACT OF THE DISCLOSUREOrganic compositions are provided containing, as a corrosion inhibitor,salts obtained by reacting an imidazoline or a diamine with analpha-substituted acetic acid.

(1) Field of the invention This invention relates to improved organiccompositions and, in one of its aspects, relates more particularly toimproved organic compositions comprising an organic base mediumsusceptible of permitting corrosive deterioration of metal surfacesunder conditions of use.

(2) Description of the prior art It is well known to those skilled inthe art that organic compositions containing organic base media, forexample oils of lubricating viscosity, lgreases, fuels, solvents andother types of liquid hydrocarbon-containing compositions aresusceptible of permitting corrosive deterioration of surfaces with whichthey come into contact, for example, oils employed as lubricants ininternal composition engines, or as lubricants for various types ofmechanical elements in which lubricants are employed, such as gear oils,cutting oils and other forms of lubricants. It is also Well known thatother organic media such as grease formulations, hydrocarbon fuels, forexample gasoline, diesel fuel, turbine fuels and hydrocarbon solventsare also capable of permitting undesirable corrosive deterioration. Inthis respect, various types of corrosion inhibitors have been suggestedto reduce or prevent undesirable corrosive deterioration. However, theincorporation of such inhibitors has nevertheless still left a need fora more effective corrosion-inhibiting eflect, particularly with respectto the use of more sophisticated presentday organic compositions of thetype hereinbefore disclosed.

SUMMARY OF THE INVENTION In accordance with the present invention,improved organic compositions comprising a major proportion of organicbase media, which would normally be susceptible of permitting corrosivedeterioration, are provided in which these compositions contain a minorproportion, sufficient to inhibit such deterioration, of a salt obtainedby reacting an imidazoline or a diamine with an alphasubstituted aceticacid having the formula:

wherein X is oxygen, sulfur or the amino group NR R is alkyl, aryl,alkaryl, aralkyl or hydrogen, and when X is NR R is an acyl orsubstituted acyl group and R is alkyl, aryl, alkaryl, aralkyl orhydrogen.

Any imidazoline or diamine may be employed for reaction with thealpha-substituted acetic acid to form the corrosion-inhibiting salt.Exemplary of the imidazoline reactant are such imidazolines as dodecenylimidazoline and heptadecenyl imidazoline. Exemplary of the diaminereactant are such diamines as3-aminomethyl-3,5,5-trimethylcyclohexylamine, N-hepta-decyl-1,3propane-diamine, ethylene diarnine and hexylene diamine. Anyalpha-substituted acetic acid having the above-described "ice structure,may be employed for reaction with the imidazoline or diamine reactants.Exemplary of such substituted acetic acids are n-octylthioacetic acid,nonyl-phenoxy-acetic acid and oleoyl-sarcosine. Reaction between theaforementioned components may be carried out at room temperature orelevated temperature as so desired.

Insofar as the specific reactants for forming the desired salt corrosioninhibiting additive are concerned, the aforementioned reactants may beemployed in stoichiometric proportions. In general, the imidazoline orthe diamine are reacted with the acid in an equivalent weight ratio offrom about 30:1 to about 0.1:1, and, preferably, in an equivalent weightratio of from about 15:1 to about 0.3 1. Insofar as the quantity of saltincorporated in the organic base medium is concerned, any amount, inminor proportion, which is sufficient to impart the desired degree ofanti-corrosion effect, may be employed. In general,.the salt is employedin an amount from about 0.001 to'abmlt 10%, and preferably in an amountfrom about 0.1fto about 5%, by weight, of the total weight of theorganic composition.

The salt may be separately preformed and thereafter incorporated in theorganic base medium, or it may be formed in situ by individuallyincorporating the aforementioned reactants in the base medium, if sodesired.

As more fully hereinafter illustrated by comparative data, it has beenfound that unexpected and significantly higher degrees ofcorrosion-inhibiting effects are realized by employing, as the corrosioninhibitor, the aforementioned reaction product of the imidazoline ordiamine with the alpha-substituted acetic acid, than is obtainedemploying the same quantity of each reactant, individually. In essence,a synergistic effect can be seen to exist by reacting the imidazoline ordiamine with the acid, rather than employing the aforementionedreactants, individually, as corrosion inhibitors, even though the samequantity of inhibitor is employed in each instance.

DESCRIPTION OF SPECIFIC EMBODIMENTS The following examples andcomparative data will serve to illustrate the novel organic compositionsof the present invention and the significant corrosion-inhibiting effectobtained by incorporating the above-described salts therein, incombination with organic base media.

In accordance 'with the data set forth in the following table, thelithium-hydroxy-stearate base grease, employed, comprised a solventrefined, naphthenic mineral oil of 56 SUS viscosity at 210 F., thickenedwith 15 wt. percent lithium hydroxy-stearate soap and 0.5 wt. percentantioxidant to a smooth grease of an unworked penetration of 220, and a60 stroke worked peneration of 228.

The calcium-acetate complex base grease comprised a solvent refined,naphthenic mineral oil of 70 SUS viscosity at 210 F., thickened by acalcium-acetate complex thickener (as shown in US. Pat. No. 2,898,297,Example 6) and 0.5 wt. percent antioxidant into a smooth grease with anunworked penetration of 246 and a 60 stroke worked penetration of 248.

The modified clay base grease comprised a paraffinic mineral oil of 62SUS viscosity at 210 F. thickened by 11 wt. percent oleo-philic claythickener (as shown in US. Pat. No. 2,531,440, Example 4), and 0.5 wt.percent anti-oxidant to a smooth grease of an unworked penetration of245 and a 60 stroke worked penetration of 265.

All grease samples, with or without added rust inhibitors, were mixed ona hot plate at 250 F. surface temperature, homogenized in a 3-roll inkmill and subjected to the standard test for determining corrosion, RustPreventive Properties of Lubricating Greases ASTM Method D-1743.

The Brine Panel Test comprised coating the freshly ground surface of acold-rolled steel panel with a grease diamine and hexylene diamine withan alpha-substituted acetic acid having the formula:

wherein X is oxygen or sulfur and R is alkyl, aryl, alkaryl, aralkyl orhydrogen.

2. A composition as defined in claim 1 wherein said salt is present inan amount from about 0.001 to about by weight.

TABLE Corrosion tests ASTM Brine Wt. Wt. Wt. D1743, panel, Example Basepercent Acid percent Grease percent rating rating 1 Heptadecenyl 0Nonyl-phenoxy- 0 Lithium hydroxy- 100 3, 3, 3 Heavy.

imidazoline. acetic acid. stearate.

0 do 99 1, 1, 1 Lightmedium 1.0 do 99 1, 1, 1 Light. 0.5 do. 99 1, 1Trace 0 Calcium estate 100 3, 3, 3 Heavy.

complex. 0 do 99 1, 1, 1 Light. 1.0 ----do 99 1, 1, 1 D0. 0.5 do 99 1,1, 1 None. 9 N-hepta-decyl- 0 Lithium hydroxy- 100 3, 3, 3 Heavy.

1, 3-pr0panestearate.

amine.

99 1, 1, 2 Light 99 1, 1, 2 Medium. d 0.5 do 99 1, l, 1 Trace. 133-amlno-methyl- 0 Nonyl-phenoxy- 100 3, 3, 3 Medium3,5,5-trimethylacetic acid. cyclohexylaml 99 1, 1, 1 Light. 99 3, 3, 3Trace. 99 1, 1, 1 Do.

As will be seen from the data of the foregoing table, a markedimprovement, in synergistic effect, with respect to corrosion inhibitionis realized by employing the combination of imidazoline or diamine withthe alpha-substituted acetic acid in forming the aforementioned saltproduct, than is obtained by employing each reactant individually,although in a similar amount as that of the salt. This effect will beapparent from the results set forth in Examples 4, 8, 12 and 16 of thetable.

It will be understood that the improved organic compositions of thepresent invention may, if so desired, contain various other additives ormixtures of such additional additives in order to further enhance theirproperties. Thus, the organic compositions of the present invention maycontain such additives as extreme pressure agents, antioxidants,antifoamants, detergents, dispersants and the like. In addition, variousother imidazolines, diamines or alpha-substituted acetic acids may beemployed in place of those hereinbefore described for purposes ofillustration. It will also be understood that although the presentinvention has been described with preferred embodiments, variousmodifications and adaptations thereof may be resorted to withoutdeparting from the spirit and scope of the invention as those skilled inthe art will readily understand.

We claim:

1. An organic composition selected from the group consisting oflubricants and normally liquid hydrocarbon fuels, susceptible ofpermitting corrosive deterioration, containing in an amount sufiicientto inhibit said deterioration, a salt obtained by reacting animidazoline selected from the group consisting of dodecenyl imidazolineand heptadecenyl imidazoline or a diamine selected from the groupconsisting of 3-aminomethyl-3,5,5-trimethy1cyclohexylamine,N-hepta-decyl-1,3-propanediamine, ethylene 3. A composition as definedin claim 1 wherein said salt is present in an amount from about 0.1 toabout 5%, by weight.

4. A composition as defined in claim 1 wherein said imidazoline or saiddiamine are reacted with said acid in an equivalent weight ratio of fromabout 30:1 to about 01:1.

5. A composition as defined in claim 1 wherein said imidazoline or saiddiamine are reacted with said acid in an equivalent Weight ratio of fromabout 15:1 to about 03:1.

6. A composition as defined in claim 1 wherein said acid isn-octylthioacetic acid.

7. A composition as defined in claim 1 wherein said acid isnonyl-phenoxy-acetic acid.

References Cited UNITED STATES PATENTS 2,907,646 10/ 1959 OKelly et al.44-63 2,919,979 l/ 1960 Martin et al. 4463 3,108,963 10/1963 Benge etal. 25251.5 A X 3,116,252 12/1963 Beretvas 252-392 X 3,314,968 4/1967Wakeman et al. 252-33.6 X 3,337,472 8/1967 Littler et al. 252-392FOREIGN PATENTS 849,126 9/1960 Great Britain 25233.6

DANIEL E. WYMAN, Primary Examiner A. H. METZ, Assistant Examiner US. Cl.X.R.

(223 UmTEo STATES PATENT omen CERTIFICATE OF CORRECTION 3,775,320 DamNovember 27, 1973 MARIO VIGO and FRITZ A BUEHLER Inventofll) It iscortifiod 'that error appears in the above-identified patent and that idLitton Patent are hereby cox-rooted an shown below:

Column 1, line 5, "Portici" should read --1\Iaple s- Signs (1 and sealedthis 23rd day of April 197L SEAL) 11171303 13 I EDWARD H .FLET JHER JR CMARSHALL DANN Atts sting Officer Commissioner of Patents $223? 111mmsm'ms PATENT omen "CERTIFICATE OF CORRECTION hu g 3,775,3 I November 27,1973 Inventor) MARIO VIGO and FRITZ A. BUEHL It is certified that errorappears in the above-identified patent and that aid Lcttora Patent arehereby corrected an shown below:

Column 1, line 5, "Portici" should read 1\Taples--.

Signed and sealed this 23rd day of April 197A.

(SEAL) INS/08:31}:

EDWARD I'-I.1T-LE" CHER ,JR., C MARSHALL DANN Attesting OfficerCommissioner of Patents

